Start in a high plank position with your arms and legs straight, shoulders above the wrists, core pulled in toward your spine.
Take a breath in, and as you exhale, bend your elbows out to the sides and lower your chest toward the ground. Stop as soon as your shoulders are in line with your elbows. As you lower, do your best not to collapse, making sure your entire body touches the floor at the same time. If it's too hard to maintain the exercise for six to eight seconds, start with a four- to six-second count.
Inhale to straighten the arms. This counts as one rep.